Pneumatic-tire-building apparatus.



P. 61 8. DE MATTIA.

PNEUMATIC TIRE BUILDING APPARATUS. I 1 APPLICATION FILED'JUNE'H. I916.

1,225,593. Patented May 8,1917.

. WITNESSES v mum/mes 7 I YATTORNEYZ? the bar 20. If not prevented, the vibration incident to the operation of building the tire on the said core would retract the bar-s16. to the end that the core would become loosened in the apparatus. In the present construction this is avoided by the angular disposition of the bars 16 to the line of pressure on the core. These lines of pressure radiate from the center of the plates H and 11, and therefore. eross the line of extension or the linear center of the bars 16. lne result of the arrangement is that the bars 16 are slightly rocked on the ridge 19 suflicient to jam thereon or become automatically locked against any retractive force exerted by the (ore supported by the said bars.

When it becomes necessary to release the core, this is accomplished by moving the plate It contra-eloelnvise when the operation of the ridge 15.) on the teeth 21 retracts the bars 16.

it will be observed that; as a result of the. lengthened channels 1?, the bars 16 are proportionally lengthened and the expansion to the. working position of said bars is materially increased over the corresponding limits of the arms disclosed in the patent above. referred to.

By emplo "ing thc'eentral convolution of the ridge. 1& and a series of teeth 21 in each of the bars 16, a considerable savingin the cost of the construction is attained as compared with that. shown in the above-mentioned patent. where the arms are provided with a single tooth and the cover plate has a spiral ridge providing a full series of convolutions.

(llamas '1. An apparatus as described emnprising a series of centering bars grouped about a central bearing. said bars be-lng movable in lines oll'sel from said bearing; means for moving said bars sinndtaneQusIy toward and away from the center of said bearing;

tively mounted on said supporting plate and i operatively engaging all of said bars for moving the same in unison for expansion and contraction thereof.

2. An apparatus as described comprisirg a series of centering bars grouped about a central bearing} said bars being movable in lines offset from said bearing; means for moving, said bars simultaneously toward and away from the center of said bearing; meansfor guiding said bars in their movement. said means embodying a rotary sup: porting plate supporting said bearing and having mid-opening channels therein for holdingsaid bars; a cover plate 'rotatively mounted on said supporting plate and operatively engaging all of said bars for mov ing the same in unison for expansion and contract-ion thereof; and means ope 'atit'ely connecting said bars and said plate, said means endnnlving rae-lc teeth on each of said bars, and a spiral ridge on said cover plate engaging said teeth.

3. An apparatus as described comprising a series of centering bars grouped about a central bearing. said bars being movable in lines ofl'set from said bearing; means for moving said bars simultaneously toward and away from the center of said bearing; means for guiding said bars in their movement, said means eml'iodying a rotary plate supporting said bearing. and having endopening channels therein for holding said bars; a cover plate relatively mounted on said supporting plate. and operutively engaging all of said bars for moving the same in unison for expansion and contraction thereof; and means operatively connecting said bars and said plate. said means embodying rack 'teeilron each of said bars, and a spiral ridge on said cover plate engaging said teeth, said teeth on said bars being carved in eorres )ondenee to the pitch of said ridge in service relation.

llt'lltlt DE MATTIA. Blilt'll IOLT) DE lilAT'lTIA.

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